ref: 6df75f7af3ccd28ad2432460cacdf853edb1113d
dir: /src/link/sdas_obj.c/
/*
* This file is part of RGBDS.
*
* Copyright (c) 2022, Eldred Habert and RGBDS contributors.
*
* SPDX-License-Identifier: MIT
*/
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "linkdefs.h"
#include "platform.h"
#include "link/assign.h"
#include "link/main.h"
#include "link/sdas_obj.h"
#include "link/section.h"
#include "link/symbol.h"
enum NumberType {
HEX = 16, // X
DEC = 10, // D
OCT = 8, // Q
};
static void consumeLF(struct FileStackNode const *where, uint32_t lineNo, FILE *file) {
if (getc(file) != '\n')
fatal(where, lineNo, "Bad line ending (CR without LF)");
}
static char const *delim = " \f\n\r\t\v"; // Whitespace according to the C and POSIX locales
static int nextLine(char **restrict lineBuf, size_t *restrict bufLen, uint32_t *restrict lineNo, struct FileStackNode const *where, FILE *file) {
retry:
++*lineNo;
int firstChar = getc(file);
switch (firstChar) {
case EOF:
return EOF;
case ';':
// Discard comment line
// TODO: if `;!FILE [...]` on the first line (`lineNo`), return it
do {
firstChar = getc(file);
} while (firstChar != EOF && firstChar != '\r' && firstChar != '\n');
// fallthrough
case '\r':
if (firstChar == '\r' && getc(file) != '\n')
consumeLF(where, *lineNo, file);
// fallthrough
case '\n':
goto retry;
}
size_t i = 0;
for (;;) {
if (i >= *bufLen) {
assert(*bufLen != 0);
*bufLen *= 2;
*lineBuf = realloc(*lineBuf, *bufLen);
if (!*lineBuf)
fatal(where, *lineNo, "Failed to realloc: %s", strerror(errno));
}
int c = getc(file);
switch (c) {
case '\r':
consumeLF(where, *lineNo, file);
// fallthrough
case '\n':
case EOF:
(*lineBuf)[i] = '\0'; // Terminate the string (space was ensured above)
return firstChar;
}
(*lineBuf)[i] = c;
++i;
}
}
static uint32_t readNumber(char const *restrict str, char const **endptr, enum NumberType base) {
uint32_t res = 0;
for (;;) {
static char const *digits = "0123456789ABCDEF";
char const *ptr = strchr(digits, toupper(*str));
if (!ptr || ptr - digits >= base) {
*endptr = str;
return res;
}
++str;
res = res * base + (ptr - digits);
}
}
static uint32_t parseNumber(struct FileStackNode const *where, uint32_t lineNo, char const *restrict str, enum NumberType base) {
if (str[0] == '\0')
fatal(where, lineNo, "Expected number, got empty string");
char const *endptr;
uint32_t res = readNumber(str, &endptr, base);
if (*endptr != '\0')
fatal(where, lineNo, "Expected number, got \"%s\"", str);
return res;
}
static uint8_t parseByte(struct FileStackNode const *where, uint32_t lineNo, char const *restrict str, enum NumberType base) {
uint32_t num = parseNumber(where, lineNo, str, base);
if (num > UINT8_MAX)
fatal(where, lineNo, "\"%s\" is not a byte", str);
return num;
}
enum AreaFlags {
AREA_TYPE = 2, // 0: Concatenate, 1: overlay
AREA_ISABS, // 0: Relative (???) address, 1: absolute address
AREA_PAGING, // Unsupported
AREA_ALL_FLAGS = 1 << AREA_TYPE | 1 << AREA_ISABS | 1 << AREA_PAGING,
};
enum RelocFlags {
RELOC_SIZE, // 0: 16-bit, 1: 8-bit
RELOC_ISSYM, // 0: Area, 1: Symbol
RELOC_ISPCREL, // 0: Normal, 1: PC-relative
RELOC_EXPR16, // Only for 8-bit size; 0: 8-bit expr, 1: 16-bit expr
RELOC_SIGNED, // 0: signed, 1: unsigned
RELOC_ZPAGE, // Unsupported
RELOC_NPAGE, // Unsupported
RELOC_WHICHBYTE, // 8-bit size with 16-bit expr only; 0: LOW(), 1: HIGH()
RELOC_EXPR24, // Only for 8-bit size; 0: follow RELOC_EXPR16, 1: 24-bit expr
RELOC_BANKBYTE, // 8-bit size with 24-bit expr only; 0: follow RELOC_WHICHBYTE, 1: BANK()
RELOC_ALL_FLAGS = 1 << RELOC_SIZE | 1 << RELOC_ISSYM | 1 << RELOC_ISPCREL | 1 << RELOC_EXPR16
| 1 << RELOC_SIGNED | 1 << RELOC_ZPAGE | 1 << RELOC_NPAGE | 1 << RELOC_WHICHBYTE
| 1 << RELOC_EXPR24 | 1 << RELOC_BANKBYTE,
};
void sdobj_ReadFile(struct FileStackNode const *where, FILE *file) {
size_t bufLen = 256;
char *line = malloc(bufLen);
char const *token;
#define getToken(ptr, ...) do { \
token = strtok((ptr), delim); \
if (!token) \
fatal(where, lineNo, __VA_ARGS__); \
} while (0)
#define expectEol(...) do { \
token = strtok(NULL, delim); \
if (token) \
fatal(where, lineNo, __VA_ARGS__); \
} while (0)
#define expectToken(expected, lineType) do { \
getToken(NULL, "'%c' line is too short", (lineType)); \
if (strcasecmp(token, (expected)) != 0) \
fatal(where, lineNo, "Malformed '%c' line: expected \"%s\", got \"%s\"", (lineType), (expected), token); \
} while (0)
if (!line)
fatal(where, 0, "Failed to alloc a line buffer: %s", strerror(errno));
uint32_t lineNo = 0;
int lineType = nextLine(&line, &bufLen, &lineNo, where, file);
enum NumberType numberType;
// The first letter (thus, the line type) identifies the integer type
switch (lineType) {
case EOF:
fatal(where, lineNo, "SDCC object only contains comments and empty lines");
case 'X':
numberType = HEX;
break;
case 'D':
numberType = DEC;
break;
case 'Q':
numberType = OCT;
break;
default:
fatal(where, lineNo, "This does not look like a SDCC object file (unknown integer format '%c')", lineType);
}
switch (line[0]) {
case 'L':
break;
case 'H':
fatal(where, lineNo, "Big-endian SDCC object files are not supported");
default:
fatal(where, lineNo, "Unknown endianness type '%c'", line[0]);
}
#define ADDR_SIZE 3
if (line[1] != '0' + ADDR_SIZE)
fatal(where, lineNo, "Unknown or unsupported address size '%c'", line[1]);
if (line[2] != '\0')
warning(where, lineNo, "Ignoring unknown characters (\"%s\") in first line", &line[2]);
// Header line
lineType = nextLine(&line, &bufLen, &lineNo, where, file);
if (lineType != 'H')
fatal(where, lineNo, "Expected header line, got '%c' line", lineType);
// Expected format: "A areas S global symbols"
getToken(line, "Empty 'H' line");
uint32_t expectedNbAreas = parseNumber(where, lineNo, token, numberType);
expectToken("areas", 'H');
getToken(NULL, "'H' line is too short");
uint32_t expectedNbSymbols = parseNumber(where, lineNo, token, numberType);
expectToken("global", 'H');
expectToken("symbols", 'H');
expectEol("'H' line is too long");
// Now, let's parse the rest of the lines as they come!
struct {
struct Section *section;
uint16_t writeIndex;
} *fileSections = NULL;
struct Symbol **fileSymbols = malloc(sizeof(*fileSymbols) * expectedNbSymbols);
size_t nbSections = 0, nbSymbols = 0;
if (!fileSymbols)
fatal(where, lineNo, "Failed to alloc file symbols table: %s", strerror(errno));
size_t nbBytes = 0; // How many bytes are in `data`, including the ADDR_SIZE "header" bytes
size_t dataCapacity = 16 + ADDR_SIZE; // SDCC object files usually contain 16 bytes per T line
uint8_t *data = malloc(sizeof(*data) * dataCapacity);
if (!data)
fatal(where, lineNo, "Failed to alloc data buffer: %s", strerror(errno));
for (;;) {
lineType = nextLine(&line, &bufLen, &lineNo, where, file);
if (lineType == EOF)
break;
switch (lineType) {
uint32_t tmp;
case 'M': // Module name
case 'O': // Assembler flags
// Ignored
break;
case 'A':
if (nbSections == expectedNbAreas)
warning(where, lineNo, "Got more 'A' lines than the expected %" PRIu32, expectedNbAreas);
fileSections = realloc(fileSections, sizeof(*fileSections) * (nbSections + 1));
if (!fileSections)
fatal(where, lineNo, "Failed to realloc file areas: %s", strerror(errno));
fileSections[nbSections].writeIndex = 0;
#define curSection (fileSections[nbSections].section)
curSection = malloc(sizeof(*curSection));
if (!curSection)
fatal(where, lineNo, "Failed to alloc new area: %s", strerror(errno));
getToken(line, "'A' line is too short");
assert(strlen(token) != 0); // This should be impossible, tokens are non-empty
curSection->name = strdup(token); // We need a pointer that will live longer
if (!curSection->name)
fatal(where, lineNo, "Failed to alloc new area's name: %s", strerror(errno));
// The following is required for fragment offsets to be reliably predicted
for (size_t i = 0; i < nbSections; ++i) {
if (!strcmp(token, fileSections[i].section->name))
fatal(where, lineNo, "Area \"%s\" already defined earlier", token);
}
expectToken("size", 'A');
getToken(NULL, "'A' line is too short");
tmp = parseNumber(where, lineNo, token, numberType);
if (tmp > UINT16_MAX)
fatal(where, lineNo, "Area \"%s\" is larger than the GB address space!?", curSection->name);
curSection->size = tmp;
expectToken("flags", 'A');
getToken(NULL, "'A' line is too short");
tmp = parseNumber(where, lineNo, token, numberType);
if (tmp & (1 << AREA_PAGING))
fatal(where, lineNo, "Internal error: paging is not supported");
curSection->isAddressFixed = tmp & (1 << AREA_ISABS);
curSection->isBankFixed = curSection->isAddressFixed;
curSection->modifier = curSection->isAddressFixed || (tmp & (1 << AREA_TYPE))
? SECTION_NORMAL : SECTION_FRAGMENT;
expectToken("addr", 'A');
getToken(NULL, "'A' line is too short");
tmp = parseNumber(where, lineNo, token, numberType);
curSection->org = tmp; // Truncation keeps the address portion only
curSection->bank = tmp >> 16;
expectEol("'A' line is too long");
// Init the rest of the members
curSection->offset = 0;
if (curSection->isAddressFixed) {
uint8_t high = curSection->org >> 8;
if (high < 0x40) {
curSection->type = SECTTYPE_ROM0;
} else if (high < 0x80) {
curSection->type = SECTTYPE_ROMX;
} else if (high < 0xA0) {
curSection->type = SECTTYPE_VRAM;
} else if (high < 0xC0) {
curSection->type = SECTTYPE_SRAM;
} else if (high < 0xD0) {
curSection->type = SECTTYPE_WRAM0;
} else if (high < 0xE0) {
curSection->type = SECTTYPE_WRAMX;
} else if (high < 0xFE) {
fatal(where, lineNo, "Areas in echo RAM are not supported");
} else if (high < 0xFF) {
curSection->type = SECTTYPE_OAM;
} else {
curSection->type = SECTTYPE_HRAM;
}
} else {
curSection->type = SECTTYPE_INVALID; // This means "indeterminate"
}
curSection->isAlignFixed = false; // No such concept!
// The array will be allocated if the section does contain data
curSection->data = NULL;
curSection->nbPatches = 0;
curSection->patches = NULL; // Same as `data`
curSection->fileSymbols = fileSymbols; // IDs are instead per-section
curSection->nbSymbols = 0;
curSection->symbols = NULL; // Will be allocated on demand as well
curSection->nextu = NULL;
#undef curSection
++nbSections;
break;
case 'S':
if (nbSymbols == expectedNbSymbols)
warning(where, lineNo, "Got more 'S' lines than the expected %" PRIu32, expectedNbSymbols);
// `realloc` is dangerous, as sections contain a pointer to `fileSymbols`.
// We can try to be nice, but if the pointer moves, it's game over!
if (nbSymbols >= expectedNbSymbols) {
struct Symbol **newFileSymbols = realloc(fileSymbols, sizeof(*fileSymbols) * (nbSymbols + 1));
if (!newFileSymbols)
fatal(where, lineNo, "Failed to alloc extra symbols: %s", strerror(errno));
if (newFileSymbols != fileSymbols)
fatal(where, lineNo, "Couldn't handle extra 'S' lines (pointer moved)");
// No need to assign, obviously
}
#define symbol (fileSymbols[nbSymbols])
symbol = malloc(sizeof(*symbol));
if (!symbol)
fatal(where, lineNo, "Failed to alloc symbol: %s", strerror(errno));
// Init other members
symbol->objFileName = where->name;
symbol->src = where;
symbol->lineNo = lineNo;
// No need to set the `sectionID`, since we can directly set the pointer
symbol->section = fileSections ? fileSections[nbSections - 1].section : NULL;
getToken(line, "'S' line is too short");
symbol->name = strdup(token);
if (!symbol->name)
fatal(where, lineNo, "Failed to alloc symbol name: %s", strerror(errno));
getToken(NULL, "'S' line is too short");
// It might be an `offset`, but both types are the same so type punning is fine
symbol->value = parseNumber(where, lineNo, &token[3], numberType);
if (symbol->section && symbol->section->isAddressFixed) {
assert(symbol->offset >= symbol->section->org);
symbol->offset -= symbol->section->org;
assert(symbol->offset <= symbol->section->size);
}
// Expected format: /[DR]ef[0-9A-F]+/i
if (token[0] == 'R' || token[0] == 'r') {
symbol->type = SYMTYPE_IMPORT;
// TODO: hard error if the rest is not zero
} else if (token[0] != 'D' && token[0] != 'd') {
fatal(where, lineNo, "'S' line is neither \"Def\" nor \"Ref\"");
} else {
// All symbols are exported
symbol->type = SYMTYPE_EXPORT;
struct Symbol const *other = sym_GetSymbol(symbol->name);
if (other) {
// The same symbol can only be defined twice if neither
// definition is in a floating section
if ((other->section && !other->section->isAddressFixed)
|| (symbol->section && !symbol->section->isAddressFixed)) {
sym_AddSymbol(symbol); // This will error out
} else if (other->value != symbol->value) {
error(where, lineNo,
"Definition of \"%s\" conflicts with definition in %s (%" PRId32 " != %" PRId32 ")",
symbol->name, other->objFileName, symbol->value, other->value);
}
} else {
// Add a new definition
sym_AddSymbol(symbol);
}
// It's fine to keep modifying the symbol after `AddSymbol`, only
// the name must not be modified
}
if (strncasecmp(&token[1], "ef", 2) != 0)
fatal(where, lineNo, "'S' line is neither \"Def\" nor \"Ref\"");
if (nbSections != 0) {
struct Section *section = fileSections[nbSections - 1].section;
++section->nbSymbols;
section->symbols = realloc(section->symbols, sizeof(section->symbols[0]) * section->nbSymbols);
if (!section->symbols)
fatal(where, lineNo, "Failed to realloc \"%s\"'s symbol list: %s", section->name, strerror(errno));
section->symbols[section->nbSymbols - 1] = symbol;
}
#undef symbol
expectEol("'S' line is too long");
++nbSymbols;
break;
case 'T':
// Now, time to parse the data!
if (nbBytes != 0)
warning(where, lineNo, "Previous 'T' line had no 'R' line (ignored)");
nbBytes = 0;
for (token = strtok(line, delim); token; token = strtok(NULL, delim)) {
if (dataCapacity == nbBytes) {
dataCapacity *= 2;
data = realloc(data, sizeof(*data) * dataCapacity);
if (!data)
fatal(where, lineNo, "Failed to realloc data buffer: %s", strerror(errno));
}
data[nbBytes] = parseByte(where, lineNo, token, numberType);
++nbBytes;
}
if (nbBytes < ADDR_SIZE)
fatal(where, lineNo, "'T' line is too short");
// Importantly, now we know that `nbBytes != 0`, which means "pending data"
break;
case 'R': // Supposed to directly follow `T`
if (nbBytes == 0) {
warning(where, lineNo, "'R' line with no 'T' line, ignoring");
break;
}
// First two bytes are ignored
getToken(line, "'R' line is too short");
getToken(NULL, "'R' line is too short");
uint16_t areaIdx;
getToken(NULL, "'R' line is too short");
areaIdx = parseByte(where, lineNo, token, numberType);
getToken(NULL, "'R' line is too short");
areaIdx |= (uint16_t)parseByte(where, lineNo, token, numberType) << 8;
if (areaIdx >= nbSections)
fatal(where, lineNo, "'R' line references area #%" PRIu16 ", but there are only %zu (so far)", areaIdx, nbSections);
assert(fileSections); // There should be at least one, from the above check
struct Section *section = fileSections[areaIdx].section;
uint16_t *writeIndex = &fileSections[areaIdx].writeIndex;
uint8_t writtenOfs = ADDR_SIZE; // Bytes before this have been written to ->data
uint16_t addr = data[0] | data[1] << 8;
if (section->isAddressFixed) {
if (addr < section->org)
fatal(where, lineNo, "'T' line reports address $%04" PRIx16 " in \"%s\", which starts at $%04" PRIx16, addr, section->name, section->org);
addr -= section->org;
}
// Lines are emitted that violate this check but contain no "payload";
// ignore those. "Empty" lines shouldn't trigger allocation, either.
if (nbBytes != ADDR_SIZE) {
if (addr != *writeIndex)
fatal(where, lineNo, "'T' lines which don't append to their section are not supported (%" PRIu16 " != %" PRIu16 ")", addr, *writeIndex);
if (!section->data) {
assert(section->size != 0);
section->data = malloc(section->size);
if (!section->data)
fatal(where, lineNo, "Failed to alloc data for \"%s\": %s", section->name, strerror(errno));
}
}
// Processing relocations is made difficult by SDLD's honestly quite bonkers
// handling of the thing.
// The way they work is that 16-bit relocs are, simply enough, writing a
// 16-bit value over a 16-bit "gap". Nothing weird here.
// 8-bit relocs, however, do not write an 8-bit value over an 8-bit gap!
// They write an 8-bit value over a 16-bit gap... and either of the two
// bytes is *discarded*. The "24-bit" flag extends this behavior to three
// bytes instead of two, but the idea's the same.
// Additionally, the "offset" is relative to *before* bytes from previous
// relocs are removed, so this needs to be accounted for as well.
// This all can be "translated" to RGBDS parlance by generating the
// appropriate RPN expression (depending on flags), plus an addition for the
// bytes being patched over.
while ((token = strtok(NULL, delim)) != NULL) {
uint16_t flags = parseByte(where, lineNo, token, numberType);
if ((flags & 0xF0) == 0xF0) {
getToken(NULL, "Incomplete relocation");
flags = (flags & 0x0F) | (uint16_t)parseByte(where, lineNo, token, numberType) << 4;
}
getToken(NULL, "Incomplete relocation");
uint8_t offset = parseByte(where, lineNo, token, numberType);
if (offset < ADDR_SIZE)
fatal(where, lineNo, "Relocation index cannot point to header (%" PRIu16 " < %u)", offset, ADDR_SIZE);
if (offset >= nbBytes)
fatal(where, lineNo, "Relocation index is out of bounds (%" PRIu16 " >= %zu)", offset, nbBytes);
getToken(NULL, "Incomplete relocation");
uint16_t idx = parseByte(where, lineNo, token, numberType);
getToken(NULL, "Incomplete relocation");
idx |= (uint16_t)parseByte(where, lineNo, token, numberType);
// Loudly fail on unknown flags
if (flags & (1 << RELOC_ZPAGE | 1 << RELOC_NPAGE))
fatal(where, lineNo, "Paging flags are not supported");
if (flags & ~RELOC_ALL_FLAGS)
warning(where, lineNo, "Unknown reloc flags 0x%x", flags & ~RELOC_ALL_FLAGS);
// Turn this into a Patch
section->patches = realloc(section->patches, sizeof(section->patches[0]) * (section->nbPatches + 1));
if (!section->patches)
fatal(where, lineNo, "Failed to alloc extra patch for \"%s\"", section->name);
struct Patch *patch = §ion->patches[section->nbPatches];
patch->lineNo = lineNo;
patch->src = where;
patch->offset = offset - writtenOfs + *writeIndex;
if (section->nbPatches != 0 && section->patches[section->nbPatches - 1].offset >= patch->offset)
fatal(where, lineNo, "Relocs not sorted by offset are not supported (%" PRIu32 " >= %" PRIu32 ")", section->patches[section->nbPatches - 1].offset, patch->offset);
patch->pcSection = section; // No need to fill `pcSectionID`, then
patch->pcOffset = patch->offset - 1; // For `jr`s
patch->type = flags & 1 << RELOC_SIZE ? PATCHTYPE_BYTE : PATCHTYPE_WORD;
uint8_t nbBaseBytes = patch->type == PATCHTYPE_BYTE ? ADDR_SIZE : 2;
uint32_t baseValue = 0;
assert(offset < nbBytes);
if (nbBytes - offset < nbBaseBytes)
fatal(where, lineNo, "Reloc would patch out of bounds (%" PRIu8 " > %zu)", nbBaseBytes, nbBytes - offset);
for (uint8_t i = 0; i < nbBaseBytes; ++i)
baseValue = baseValue | data[offset + i] << (8 * i);
// Extra size that must be reserved for additional operators
#define RPN_EXTRA_SIZE (5 + 1 + 5 + 1 + 5 + 1) // >> 8 & $FF, then + <baseValue>
#define allocPatch(size) do { \
patch->rpnSize = (size); \
patch->rpnExpression = malloc(patch->rpnSize + RPN_EXTRA_SIZE); \
if (!patch->rpnExpression) \
fatal(where, lineNo, "Failed to alloc RPN expression: %s", strerror(errno)); \
} while (0)
// Bit 4 specifies signedness, but I don't think that matters?
// Generate a RPN expression from the info and flags
if (flags & 1 << RELOC_ISSYM) {
if (idx >= nbSymbols)
fatal(where, lineNo, "Reloc refers to symbol #%" PRIu16 " out of %zu", idx, nbSymbols);
struct Symbol const *sym = fileSymbols[idx];
// SDCC has a bunch of "magic symbols" that start with a
// letter and an underscore. These are not compatibility
// hacks, this is how SDLD actually works.
if (sym->name[0] == 'b' && sym->name[1] == '_') {
// Look for the symbol being referenced, and use its index instead
for (idx = 0; idx < nbSymbols; ++idx) {
if (strcmp(&sym->name[1], fileSymbols[idx]->name) == 0)
break;
}
if (idx == nbSymbols)
fatal(where, lineNo, "\"%s\" is missing a reference to \"%s\"", sym->name, &sym->name[1]);
allocPatch(5);
patch->rpnExpression[0] = RPN_BANK_SYM;
patch->rpnExpression[1] = idx;
patch->rpnExpression[2] = idx >> 8;
patch->rpnExpression[3] = idx >> 16;
patch->rpnExpression[4] = idx >> 24;
} else if (sym->name[0] == 'l' && sym->name[1] == '_') {
allocPatch(1 + strlen(&sym->name[2]) + 1);
patch->rpnExpression[0] = RPN_SIZEOF_SECT;
strcpy((char *)&patch->rpnExpression[1], &sym->name[2]);
} else if (sym->name[0] == 's' && sym->name[1] == '_') {
allocPatch(1 + strlen(&sym->name[2]) + 1);
patch->rpnExpression[0] = RPN_STARTOF_SECT;
strcpy((char *)&patch->rpnExpression[1], &sym->name[2]);
} else {
allocPatch(5);
patch->rpnExpression[0] = RPN_SYM;
patch->rpnExpression[1] = idx;
patch->rpnExpression[2] = idx >> 8;
patch->rpnExpression[3] = idx >> 16;
patch->rpnExpression[4] = idx >> 24;
}
} else {
if (idx >= nbSections)
fatal(where, lineNo, "Reloc refers to area #%" PRIu16 " out of %zu", idx, nbSections);
// It gets funky. If the area is absolute, *actually*, we
// must not add its base address, as the assembler will
// already have added it in `baseValue`.
// We counteract this by subtracting the section's base
// address from `baseValue`, undoing what the assembler did;
// this allows the relocation to still be correct, even if
// the section gets moved for any reason.
if (fileSections[idx].section->isAddressFixed)
baseValue -= fileSections[idx].section->org;
char const *name = fileSections[idx].section->name;
struct Section const *other = sect_GetSection(name);
// Unlike with `s_<AREA>`, referencing an area in this way
// wants the beginning of this fragment, so we must add the
// fragment's (putative) offset to account for this.
// The fragment offset prediction is guaranteed since each
// section can only have one fragment per SDLD object file,
// so this fragment will be appended to the existing section
// *if any*, and thus its offset will be the section's
// current size.
if (other)
baseValue += other->size;
allocPatch(1 + strlen(name) + 1);
patch->rpnSize = 1 + strlen(name) + 1;
patch->rpnExpression = malloc(patch->rpnSize + RPN_EXTRA_SIZE);
if (!patch->rpnExpression)
fatal(where, lineNo, "Failed to alloc RPN expression: %s", strerror(errno));
patch->rpnExpression[0] = RPN_STARTOF_SECT;
// The cast is fine, it's just different signedness
strcpy((char *)&patch->rpnExpression[1], name);
}
#undef allocPatch
patch->rpnExpression[patch->rpnSize] = RPN_CONST;
patch->rpnExpression[patch->rpnSize + 1] = baseValue;
patch->rpnExpression[patch->rpnSize + 2] = baseValue >> 8;
patch->rpnExpression[patch->rpnSize + 3] = baseValue >> 16;
patch->rpnExpression[patch->rpnSize + 4] = baseValue >> 24;
patch->rpnExpression[patch->rpnSize + 5] = RPN_ADD;
patch->rpnSize += 5 + 1;
if (patch->type == PATCHTYPE_BYTE) {
// Despite the flag's name, as soon as it is set, 3 bytes
// are present, so we must skip two of them
if (flags & 1 << RELOC_EXPR16) {
if (*writeIndex + (offset - writtenOfs) > section->size)
fatal(where, lineNo, "'T' line writes past \"%s\"'s end (%u > %" PRIu16 ")", section->name, *writeIndex + (offset - writtenOfs), section->size);
// Copy all bytes up to those (plus the byte that we'll overwrite)
memcpy(§ion->data[*writeIndex], &data[writtenOfs], offset - writtenOfs + 1);
*writeIndex += offset - writtenOfs + 1;
writtenOfs = offset + 3; // Skip all three `baseValue` bytes, though
}
// Append the necessary operations...
if (flags & 1 << RELOC_ISPCREL) {
// The result must *not* be truncated for those!
patch->type = PATCHTYPE_JR;
// TODO: check the other flags?
} else if (flags & 1 << RELOC_EXPR24 && flags & 1 << RELOC_BANKBYTE) {
patch->rpnExpression[patch->rpnSize] = RPN_CONST;
patch->rpnExpression[patch->rpnSize + 1] = 16;
patch->rpnExpression[patch->rpnSize + 2] = 16 >> 8;
patch->rpnExpression[patch->rpnSize + 3] = 16 >> 16;
patch->rpnExpression[patch->rpnSize + 4] = 16 >> 24;
patch->rpnExpression[patch->rpnSize + 5] = flags & 1 << RELOC_SIGNED ? RPN_SHR : RPN_USHR;
patch->rpnSize += 5 + 1;
} else {
if (flags & 1 << RELOC_EXPR16 && flags & 1 << RELOC_WHICHBYTE) {
patch->rpnExpression[patch->rpnSize] = RPN_CONST;
patch->rpnExpression[patch->rpnSize + 1] = 8;
patch->rpnExpression[patch->rpnSize + 2] = 8 >> 8;
patch->rpnExpression[patch->rpnSize + 3] = 8 >> 16;
patch->rpnExpression[patch->rpnSize + 4] = 8 >> 24;
patch->rpnExpression[patch->rpnSize + 5] = flags & 1 << RELOC_SIGNED ? RPN_SHR : RPN_USHR;
patch->rpnSize += 5 + 1;
}
patch->rpnExpression[patch->rpnSize] = RPN_CONST;
patch->rpnExpression[patch->rpnSize + 1] = 0xFF;
patch->rpnExpression[patch->rpnSize + 2] = 0xFF >> 8;
patch->rpnExpression[patch->rpnSize + 3] = 0xFF >> 16;
patch->rpnExpression[patch->rpnSize + 4] = 0xFF >> 24;
patch->rpnExpression[patch->rpnSize + 5] = RPN_AND;
patch->rpnSize += 5 + 1;
}
} else if (flags & 1 << RELOC_ISPCREL) {
assert(patch->type == PATCHTYPE_WORD);
fatal(where, lineNo, "16-bit PC-relative relocations are not supported");
} else if (flags & (1 << RELOC_EXPR16 | 1 << RELOC_EXPR24)) {
fatal(where, lineNo, "Flags 0x%x are not supported for 16-bit relocs", flags & (1 << RELOC_EXPR16 | 1 << RELOC_EXPR24));
}
++section->nbPatches;
}
// If there is some data left to append, do so
if (writtenOfs != nbBytes) {
assert(nbBytes > writtenOfs);
if (*writeIndex + (nbBytes - writtenOfs) > section->size)
fatal(where, lineNo, "'T' line writes past \"%s\"'s end (%zu > %" PRIu16 ")", section->name, *writeIndex + (nbBytes - writtenOfs), section->size);
memcpy(§ion->data[*writeIndex], &data[writtenOfs], nbBytes - writtenOfs);
*writeIndex += nbBytes - writtenOfs;
}
nbBytes = 0; // Do not allow two R lines to refer to the same T line
break;
case 'P':
default:
warning(where, lineNo, "Unknown/unsupported line type '%c', ignoring", lineType);
break;
}
}
if (nbBytes != 0)
warning(where, lineNo, "Last 'T' line had no 'R' line (ignored)");
if (nbSections < expectedNbAreas)
warning(where, lineNo, "Expected %" PRIu32 " 'A' lines, got only %zu", expectedNbAreas, nbSections);
if (nbSymbols < expectedNbSymbols)
warning(where, lineNo, "Expected %" PRIu32 " 'S' lines, got only %zu", expectedNbSymbols, nbSymbols);
nbSectionsToAssign += nbSections;
for (size_t i = 0; i < nbSections; ++i) {
struct Section *section = fileSections[i].section;
// RAM sections can have a size, but don't get any data (they shouldn't have any)
if (fileSections[i].writeIndex != section->size && fileSections[i].writeIndex != 0)
fatal(where, lineNo, "\"%s\" was not fully written (%" PRIu16 " < %" PRIu16 ")", section->name, fileSections[i].writeIndex, section->size);
// This must be done last, so that `->data` is not NULL anymore
sect_AddSection(section);
if (section->modifier == SECTION_FRAGMENT) {
// Add the fragment's offset to all of its symbols
for (uint32_t j = 0; j < section->nbSymbols; ++j)
section->symbols[j]->offset += section->offset;
}
}
#undef expectEol
#undef expectToken
#undef getToken
free(fileSections);
free(data);
fclose(file);
}